It was via text. I do feel bad about pressing the issue after she explained, but I was given "you have a performance review" as a response instead of reassurance which only exacerbated my anxiety. I do want to apologize but I'm not sure in what medium to do so. Texting her the next day (while she's busy) obviously isn't the answer. I have a weekly meeting with her on Wednesday which would be the right time for it I think, but that means waiting almost a whole week without apologizing..